Which sharpening angle for which knife?

The most common question in knife sharpening is: 15 or 20 degrees? The honest answer: the number matters less than everyone thinks. What matters is that the angle stays the same throughout the pull. Here is which value suits which blade — and why most people fail at the angle, not at the number.

Sharpening angle or cutting angle? Two numbers that get mixed up

The sharpening angle is the angle of one side to the centre line of the blade. The cutting angle is the angle of the finished edge, both sides together.

A knife with a 20° sharpening angle has a 40° cutting angle. Mix the two up and you end up grinding twice as flat or twice as steep as intended. When a number appears without explanation, it is almost always the sharpening angle per side.

Which angle suits which knife

These are common guide values, not laws — every maker differs a little:

Blade	Sharpening angle (per side)	Why
Japanese blades, Damascus, santoku	approx. 10–15°	hard steel, takes a fine edge
European chef's and utility knives	approx. 17–20°	softer steel, needs stability
Bread and serrated knives	usually single-bevel	own logic, see separate page
Hunting, fishing and outdoor knives	approx. 20–25°	has to survive bone and wood
Hatchets, machetes	approx. 25–30°	impact load

The rule of thumb: the finer the work, the flatter the angle. The rougher the load, the blunter — and therefore more durable — the edge has to be. A chef's knife ground too flat cuts impressively and chips on the first pumpkin.

Why almost everyone fails at the angle, not the number

Sharpening by hand on a stone means holding the same angle over twenty or thirty pulls. Two degrees of drift already change the result: sometimes you remove material above the edge, sometimes below it. The edge turns round instead of sharp, and you grind longer and longer without getting better.

So the honest order of priorities is:

A steady angle — that accounts for 90% of the result.
The right grit — coarse to reset the edge, fine to hone it.
The exact number of degrees — the smallest lever, and the one most talked about.

How Vulkanus solves it

Our devices do not give you two fixed detents to choose between. The sharpening system adjusts itself to the blade within a range of 11° to 21°. You set the knife down and pull it through — the device holds the angle, not your hand.

That has two consequences:

You do not have to decide whether your knife wants 15° or 20°. The range covers everything from a fine Japanese chef's knife to a sturdy European utility blade.
You need no practice. The most common mistake — the wandering angle — is ruled out by design.

Three to five pulls and the blade is sharp. No water, no oil, no stone.

Frequently asked questions

Will I damage my Japanese knife by sharpening it at 20°?

You will not damage it, but you take away its strength: the fine edge you paid for becomes more stable and therefore coarser. The reverse applies too — a European chef's knife ground to 12° cuts beautifully and chips on the first hard cut.

How do I know the factory angle of my knife?

Usually it is not stated. For everyday use that does not matter: if you sharpen within a range that suits the type of blade, the angle settles itself after a few passes.

What about single-bevel blades?

Traditional Japanese blades such as yanagiba or deba are ground on one side only. The same is true of most serrations. How to handle those is on the page sharpening serrated knives.

Do I still need to hone after sharpening?

On a whetstone, yes — a burr is left on the edge, and as long as it is there the knife is not truly sharp. On our devices the second movement takes care of it: pulling through with the tip tilted upwards removes the burr.